Both classes are very difficult to play until the pets start to come into their own. For a hunter, you probably won't get the knack of how to use your pet until about level 12. (It IS possible to just fight and use your pet for side damage, but its rather hard to play that way and rely on using Mongoose Bite for damage.)
I haven't really played warlock to compare. I got annoyed with the class around level 6, but it also really isn't my style.
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